Cyber Resilience

CVE-2021-38371

High

Published: 10 August 2021

Published
10 August 2021
Modified
03 November 2025
KEV Added
—
Patch
—
CVSS Score v3.1 7.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N
EPSS Score 0.0221 84.8th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-38371 is a high-severity Injection (CWE-74) vulnerability in Exim Exim. Its CVSS base score is 7.5 (High).

Operationally, ranked in the top 15.2% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

The STARTTLS feature in Exim through 4.94.2 allows response injection (buffering) during MTA SMTP sending.

CWE(s)
CWE-74

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

exim
exim
≤ 4.94.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

SA-11 Developer Testing and Evaluation
addresses: CWE-74

Developer assessments and testing (including injection-focused techniques) identify improper neutralization of special elements, and the verifiable flaw remediation corrects them pre-deployment.

SI-4 System Monitoring
addresses: CWE-74

Identifies indicators of injection attacks (command, SQL, LDAP, etc.) via anomaly and attack monitoring.

References